Adobe COLDFUSION 9 Manual page 177

DEVELOPING COLDFUSION 9 APPLICATIONS
Building Blocks of ColdFusion Applications
Code
function TotalInterest(principal, annualPercent, months) {
Var years = 0;
Var interestRate = 0;
Var totalInterest = 0;
principal = trim(principal);
principal = REReplace(principal,"[\$,]","","ALL");
annualPercent = Replace(annualPercent,"%","","ALL");
interestRate = annualPercent / 100;
years = months / 12;
totalInterest = principal*
(((1+ interestRate)^years)-1);
Return DollarFormat(totalInterest);
}
Defining the function using the cffunction tag
The following code replaces CFScript statements with their equivalent CFML tags.
<cffunction name="TotalInterest">
<cfargument name="principal" required="Yes">
<cfargument name="annualPercent" required="Yes">
<cfargument name="months" required="Yes">
<cfset var years = 0>
<cfset var interestRate = 0>
<cfset var totalInterest = 0>
<cfset principal = trim(principal)>
<cfset principal = REReplace(principal,"[\$,]","","ALL")>
<cfset annualPercent = Replace(annualPercent,"%","","ALL")>
<cfset interestRate = annualPercent / 100>
<cfset years = months / 12>
<cfset totalInterest = principal*
(((1+ interestRate)^years)-1)>
<cfreturn DollarFormat(totalInterest)>
</cffunction>
Using UDFs effectively
Many techniques help you use user-defined functions more effectively.
Using functions in ColdFusion component
In many cases, the most effective use of UDFs is within a CFC. For more information on CFCs, see
ColdFusion Components" on page 177.
Description
Starts the
Requires three variables: the principal amount, the
annual percentage rate, and the loan duration in
months.
Declares intermediate variables used in the function
and initializes them to 0. All
precede the rest of the function code.
Removes any leading or trailing spaces from the
principal argument. Removes any dollar sign ($) and
comma (,) characters from the principal argument to
get a numeric value.
Removes any percent (%) character from the
annualPercent
then divides the percentage value by 100 to get the
interest rate.
Converts the loan from months to years.
Calculates the total amount of interest due. It is possible
to calculate the value in the
example uses an intermediate totalInterest variable to
make the code easier to read. Returns the result
formatted as a US currency string.
Ends the function definition.
Last updated 8/5/2010
function definition.
TotalInterest
var statements must
argument to get a numeric value,
statement, but this
Return
"Building and Using
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